Gamma spectrometric measurement of uranium isotopic composition and mass in sintered UO2 pellets using the efficiency transfer method.

Gamma spectrometric measurements to determine the isotopic composition and total uranium mass in UO2 pellets (D = 7.5 mm; H = 3.5 mm, ρ = 10 g/cm3) were carried out. The required efficiency curve was obtained by applying the efficiency transfer method from a calibration standard (D = 65 mm; H = 20 mm) of a slightly acidified water solution. The average isotopic composition of ten UO2 pellets was consistent with values of natural uranium given by IUPAC. The average relative bias for the 235U/238U amount ratio was -0.73% using the 1001 keV gamma line for 238U and 0.50% using the 63 keV gamma line (186 keV was always used for 235U). For the total uranium mass, the mean deviation as compared to mass determinations using a balance was 5.5% using the 1001 keV gamma line for 238U and 4.3% using the 63 keV gamma line.

Factors associated with changes in volumetric bone mineral density and cortical area in men with ankylosing spondylitis: a 5-year prospective study using HRpQCT.

Patients with ankylosing spondylitis (AS) have impaired volumetric bone mineral density (vBMD) assessed with high-resolution peripheral computed tomography (HRpQCT). This first longitudinal HRpQCT study in AS shows that cortical and trabecular vBMD decreased at tibia and that signs of inflammation were associated with cortical bone loss at tibia and radius. INTRODUCTION: Patients with ankylosing spondylitis (AS) have reduced volumetric bone mineral density (vBMD) in the peripheral skeleton assessed with high-resolution peripheral quantitative computed tomography (HRpQCT). The aims were to investigate longitudinal changes in vBMD, cortical area, and microarchitecture and to assess factors associated with changes in vBMD and cortical area in men with AS. METHODS: HRpQCT of radius and tibia was performed in 54 men with AS at baseline and after 5 years. Univariate and multivariable linear regression analyses were used. RESULTS: At tibia, there were significant decreases exceeding least significant changes (LSC) in cortical and trabecular vBMD, mean (SD) percent change -1.0 (1.9) and -2.7 (5.0) respectively (p<0.001). In multivariable regression analyses, increase in disease activity measured by ASDAS_CRP from baseline to follow-up was associated with decreases in cortical vBMD (ß -0.86, 95% CI -1.31 to -0.41) and cortical area (ß -1.66, 95% CI -3.21 to -0.10) at tibia. At radius, no changes exceeded LSC. Nonetheless, increase in ASDAS_CRP was associated with decreases in cortical vBMD, and high time-averaged ESR was associated with decreases in cortical area. Treatment with TNF inhibitor ≥ 4 years during follow-up was associated with increases in cortical vBMD and cortical area at tibia, whereas exposure to bisphosphonates was associated with increases in cortical measurements at radius. No disease-related variables or treatments were associated with changes in trabecular vBMD. CONCLUSION: The findings in this first longitudinal HRpQCT study in patients with AS strengthen the importance of controlling disease activity to maintain bone density in the peripheral skeleton.

Pre-oxygenation using high-flow nasal oxygen vs. tight facemask during rapid sequence induction.

Pre-oxygenation using high-flow nasal oxygen can decrease the risk of desaturation during rapid sequence induction in patients undergoing emergency surgery. Previous studies were single-centre and often in limited settings. This randomised, international, multicentre trial compared high-flow nasal oxygen with standard facemask pre-oxygenation for rapid sequence induction in emergency surgery at all hours of the day and night. A total of 350 adult patients from six centres in Sweden and one in Switzerland undergoing emergency surgery where rapid sequence induction was required were included and randomly allocated to pre-oxygenation with 100% oxygen using high-flow nasal oxygen or a standard tight-fitting facemask. The primary outcome was the number of patients developing oxygen saturations <93% from the start of pre-oxygenation until 1 min after tracheal intubation. Data from 349 of 350 patients who entered the study were analysed (174 in the high-flow nasal oxygen group and 175 in the facemask group). No difference was detected in the number of patients desaturating <93%, five (2.9%) vs. six (3.4%) patients in the high-flow nasal oxygen and facemask group, respectively (p = 0.77). The risk of desaturation was not increased during on-call hours. No difference was seen in end-tidal carbon dioxide levels in the first breath after tracheal intubation or in the number of patients with signs of regurgitation between groups. These results confirm that high-flow nasal oxygen maintains adequate oxygen levels during pre-oxygenation for rapid sequence induction.

Reoperation for persistent pain after groin hernia surgery: a population-based study.

PURPOSE: The aim of the present study was to assess the outcome results after reoperation for persistent pain after hernia surgery in a population-based setting. METHODS: All patients who had undergone surgery for persistent pain after previous groin hernia surgery 1999-2006 were identified in the Swedish Hernia Register (n = 237). Data on the surgical technique used were abstracted from the medical records. The patients were asked to answer a set of questions including SF-36 to evaluate the prevalence of pain after reoperation. RESULTS: The study group consisted of 95 males and 16 females, mean age 53 years. In 27 % of cases an intervention aimed at suspected ilioinguinal neuralgia was performed. The mesh was removed completely in 28% and partially in 13%. A suture at the pubic tubercle was removed in 13% of cases. Decrease in pain after the most recent reoperation was reported by 69 patients (62%), no change in pain by 21 patients (19%) and increase in pain in 21 patients (19%). There was no significant difference in outcome between mesh removal, removal of sutures at the tubercle or interventions aimed at the ilioinguinal nerve. All subscales of SF-36 were significantly reduced when compared to the age- and gender-matched general population (p < 0.05). CONCLUSIONS: Patients reoperated for persistent pain after hernia surgery often report a reduction in pain, but the natural course of persistent pain, the relatively low response rate and selection of patients make it difficult to draw definite conclusions.

Betamethasone in hernia surgery: a randomized controlled trial.

BACKGROUND: Post-operative pain and nausea may be a problem in day-case surgery. This study aims to investigate the effect of betamethasone on pain and nausea in inguinal hernia surgery. METHODS: Patients aged 18-70 years scheduled for open inguinal hernia surgery at two Swedish hospitals, March 2005-December 2009, were eligible for inclusion. Patients were randomized, to either treatment with 12 mg betamethasone intravenously or placebo. Post-operative pain was assessed using a visual analogue scale on the recovery ward, each day the first post-operative week and at 1 month after surgery. One year after surgery, residual pain was estimated by the Inguinal Pain Questionnaire. RESULTS: A total of 398 patients were included (21 women, 377 men). Pain at rest on the day of surgery was significantly lower in the treatment group (p = 0.012). The pain was also significantly lower in the treatment group the day after surgery (p < 0.001), but not during the remaining part of the first post-operative week. Bleeding complications were reported by 17 patients (8.5%) in the Betamethasone group and seven (3.5%) in the placebo group (p = 0.028). One month after surgery, 21 out of 173 (12%) in the betamethasone group still had pain, compared to 33 out of 159 (21%) in the placebo arm (p = 0.049). After 1 year, no significant difference in pain was seen. CONCLUSION: A 12 mg betamethasone reduced pain during the first 24 h and at 1 month after inguinal hernia surgery. If combined with diclofenac, however, this dose may increase the risk for bleeding complications.

Characterizing uranium oxide reference particles for isotopic abundances and uranium mass by single particle isotope dilution mass spectrometry.

Uranium and plutonium particulate test materials are becoming increasingly important as the reliability of measurement results has to be demonstrated to regulatory bodies responsible for maintaining effective nuclear safeguards. In order to address this issue, the Institute for Reference Materials and Measurements (IRMM) in collaboration with the Institute for Transuranium Elements (ITU) has initiated a study to investigate the feasibility of preparing and characterizing a uranium particle reference material for nuclear safeguards, which is finally certified for isotopic abundances and for the uranium mass per particle. Such control particles are specifically required to evaluate responses of instruments based on mass spectrometric detection (e.g. SIMS, TIMS, LA-ICPMS) and to help ensuring the reliability and comparability of measurement results worldwide. In this paper, a methodology is described which allows quantifying the uranium mass in single micron particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS). This methodology is characterized by substantial improvements recently achieved at IRMM in terms of sensitivity and measurement accuracy in the field of uranium particle analysis by TIMS. The use of monodisperse uranium oxide particles prepared using an aerosol generation technique developed at ITU, which is capable of producing particles of well-characterized size and isotopic composition was exploited. The evidence of a straightforward correlation between the particle volume and the mass of uranium was demonstrated in this study. Experimental results have shown that the uranium mass per particle can be measured via the ID-TIMS method to a relative expanded uncertainty of about 10% (coverage factor k=2). The availability of reliable and validated methods for the characterization of uranium particles is considered to be essential for the establishment of SI-traceable measurement results. It is therefore expected that the method developed in this study is valuable for the certification of particulate materials in which the isotopic composition and the content of uranium must be accurately known.

The time profile of groin hernia recurrences.

PURPOSE: If the pathogeneses of the development of a recurrence varies following the different methods of hernia repair, the time required to develop a recurrence could be expected to vary. The aim of the study was to identify risk factors affecting the time interval between the primary repair and the reoperation. METHODS: Data from the Swedish Hernia Register were used. Each year of the 5-year follow-up period was treated as a separate subgroup and merged together into one large group. For each risk factor, we performed a Cox proportional hazard analysis, testing for interactions between the year and the risk factor, with reoperation as the endpoint. RESULTS: Altogether, 142,578 repairs were recorded, of which 7.7% were performed on women. The mean age of the cohort was 59 years. The overall recurrence rate in the 5-year period was 4.3%. Multivariate analysis showed that recurrence following surgery for recurrent hernia occurred relatively early (P < 0.05).Recurrence also appeared early if postoperative complications were registered (P < 0.05). Recurrence after suture repair or laparoscopic repair appeared relatively early compared to recurrence following open mesh repair (P < 0.05). In a separate analysis, a relatively higher risk for early recurrence was seen for all sutured repairs compared to all mesh repairs (P < 0.05). CONCLUSIONS: The pathogenesis behind the development of recurrence probably differs depending on the technique applied during the hernia repair. The higher proportion of early recurrences following laparoscopic repair, suture repair and recurrent repair may be explained by the high proportion of technical failures.

Sugar fermentation in probiotic bacteria--an in vitro study.

INTRODUCTION: Food supplemented with probiotic bacteria is a rapidly growing sector of the market. The aim of the present study was to evaluate and compare the acid production of selected probiotic strains available in commercial products. METHODS: Six Lactobacillus strains (Lactobacillus plantarum 299v and 931; Lactobacillus rhamnosus GG and LB21; Lactobacillus paracasei subsp. paracasei F19, and Lactobacillus reuteri PTA 5289) were cultivated at 37 degrees C in an anaerobic atmosphere on Man, Rogosa, Shape (MRS) agar for 48 h or MRS broth for 16 h. After centrifugation, the cells were washed and resuspended in sterile phosphate-buffered saline and immediately subjected to a fermentation assay with 12 different carbohydrates (nine sugars and three sugar alcohols) in microtiter plates with a pH indicator. The plates were examined for color changes after 24, 48, and 72 h of incubation under aerobic and anaerobic conditions. Three scores were used: negative (pH > 6.8); weak (pH 5.2-6.8), and positive (pH < 5.2). The strains were characterized with the API 50 CH system to confirm their identity. RESULTS: L. plantarum fermented all the sugars except for melibiose, raffinose, and xylitol. Both L. rhamnosus strains were generally less active although L. rhamnosus GG was slightly more active than strain LB21 in the 5% CO(2) setting. The latter strain exhibited negative reactions for sucrose, maltose, arabinose, and sorbitol under anaerobic conditions. The assays with L. paracasei and L. reuteri had negative or weak reactions for all tested sugars under both aerobic and anaerobic conditions. CONCLUSION: The metabolic capacity to form acid from dietary sugars differed significantly between the various probiotic strains.

Transgenic mice overexpressing human acetylcholinesterase and the Swedish amyloid precursor protein mutation: effect of nicotine treatment.

Acetylcholinesterase (AChE) is shown to promote deposition of beta-amyloid (Abeta) peptides and to enhance Abeta toxicity. Tg2576 (transgenic mice carrying the Swedish mutation of amyloid precursor protein, APPswe) mice and mice overexpressing human synaptic acetylcholinesterase (AChE-S) were crossed (hAChE-Tg//APPswe), to study the effects of brain Abeta, from 1 to 10 months of age, under the constant influence of AChE-S. The effect of nicotine treatment was also evaluated in these mice since we have previously shown that nicotine dramatically decreases Abeta levels in single transgenic APPswe mice. Already at 1 and 3 months, hAChE-Tg// APPswe mice showed increased levels of cortical insoluble Abeta1-40 and Abeta1-42 compared with APPswe mice, whereas APPswe mice displayed increased soluble Abeta1-40. Abeta plaques were detected at 7 months, thus before onset of plaque formation in APPswe mice. No differences were found in [125I]alpha-bungarotoxin binding sites or hippocampal glial fibrillary acidic protein (GFAP) immunoreactivity between hAChE-Tg//APPswe, and APPswe mice at either 1 or 10 months of age. L(-)-Nicotine (final dose 0.45 mg/kg) treatment twice daily for 10 days to 14-month-old hAChE-Tg// APPswe mice increased cortical insoluble Abeta1-40 levels, while both L(-)- and D(+)-nicotine (final dose 0.45 mg/kg) increased soluble Abeta1-42. L(-)-Nicotine reduced hippocampal GFAP immunoreactivity both in hAChE-Tg//APPswe mice and non-transgenic controls, while D(+)-nicotine caused a decrease only in hAChE-Tg//APPswe mice. Moreover, D(+)-nicotine increased the [125I]alpha-bungarotoxin binding sites in the hippocampus, and cortex of the hAChE-Tg//APPswe mice. In conclusion, already at a very young age, hAChE-Tg// APPswe mice exhibit increased levels of aggregated Abeta compared with APPswe mice, due to the possible interaction between Abeta and AChE-S, whereas APPswe mice exhibit increased soluble Abeta. The interaction between Abeta and AChE-S may also explain the different effect of nicotine on Abeta pathology in the hAChE-Tg//APPswe mice. The results in this study emphasize the importance of using different transgenic mouse models for evaluating the effect of new drug candidates for the treatment of Alzheimer's disease.

European surveillance study on antimicrobial susceptibility of Gram-positive anaerobic cocci.

Gram-positive anaerobic cocci (GPAC) are a heterogeneous group of microorganisms frequently isolated from local and systemic infections. In this study, the antimicrobial susceptibilities of clinical strains isolated in 10 European countries were investigated. After identification of 299 GPAC to species level, the minimum inhibitory concentrations of penicillin, imipenem, clindamycin, metronidazole, vancomycin and linezolid were determined by the agar dilution method according to the Clinical and Laboratory Standards Institute. The majority of isolates were identified as Finegoldia magna and Parvimonas micra (formerly Peptostreptococcus micros), isolated from skin and soft tissue infections. All isolates were susceptible to imipenem, metronidazole, vancomycin and linezolid. Twenty-one isolates (7%) were resistant to penicillin (n=13) and/or to clindamycin (n=12). Four isolates were resistant to both agents. The majority of resistant isolates were identified as F. magna and originated from blood, abscesses and soft tissue infections.

Examination of cfiA-mediated carbapenem resistance in Bacteroides fragilis strains from a European antibiotic susceptibility survey.

Of 1284 Bacteroides strains collected in Europe in 2000 for antibiotic susceptibility surveillance, 65 isolates displayed imipenem minimum inhibitory concentrations (MICs) > or =1 mg/L and were chosen for a thorough analysis of their resistance mechanism. Twenty-five of the isolates were positive for the cfiA carbapenem resistance gene. The resistance rates were 0.8% and 1.3% for imipenem and meropenem, respectively. In six of the strains, insertion sequence (IS) elements (IS613, IS614B, IS1186 and IS1187) activated the cfiA gene. However, other strains displayed at least elevated carbapenem MICs or were carbapenem resistant and produced measurable carbapenemase activities but did not harbour IS elements in the region upstream of the cfiA gene. The major determinant of carbapenem resistance in Bacteroides fragilis is production of CfiA metallo-beta-lactamase via activation of the cfiA gene by IS elements (higher level resistance) or by activation of its putative own promoter.

31P MRS evaluation of fatigue in anterior tibial muscle in postpoliomyelitis patients and healthy volunteers.

Changes in concentration of high energy phosphates and pH were studied during rest, exercise and subsequent recovery in the anterior tibial muscle of 10 patients with late effects of poliomyelitis and 10 age- and sex-matched healthy volunteers using 31P MRS. The exercise was dynamic and isometric, and the force levels were individually adapted to each subject and stepwise increased. In general, there were no differences in metabolite changes between the groups, except for lower Pi and Pi/PCr for the volunteers during the recovery phase, also reflected by shorter recovery half-time for Pi. The interindividual variation was much higher for the patient group. Some of the patients showed deviating results probably because of differences in muscle fibre type.

Antimicrobial susceptibility of Bacteroides fragilis group isolates in Europe.

OBJECTIVE: To evaluate the activity of old and newer antianaerobic drugs against clinical isolates of Bacteroides fragilis group strains from different parts of Europe. METHODS: Bacteroides fragilis group isolates from 37 laboratories in 19 countries were biochemically characterized. The MICs of seven antimicrobial agents were determined by the agar dilution method as recommended by the NCCLS. Production of beta-lactamase was detected by nitrocefin. RESULTS: There were 1284 B. fragilis group isolates included in the study. Abdominal infections and wounds were the most common sources of isolation and B. fragilis was the dominating species. Ninety-nine percent of the strains were resistant to ampicillin (breakpoint 2 mg/L), 6% to cefoxitin (64 mg/L), 15% to clindamycin (8 mg/L) and 9% to moxifloxacin (8 mg/L). Less than 1% were resistant to imipenem (16 mg/L), piperacillin-tazobactam (128 mg/L) and metronidazole (32 mg/L). Ninety-six percent of the isolates were beta-lactamase producers. CONCLUSIONS: Antimicrobial resistance among the B. fragilis group is increasing.

Depleted uranium particles in selected Kosovo samples.

Selected soil samples, collected in Kosovo locations where DU ammunition was expended during the 1999 Balkan conflict, have been investigated by secondary ion mass spectrometry (SIMS), X-ray fluorescence imaging using a micro-beam (micro-XRF) and scanning electron microscopy equipped with an energy dispersive X-ray fluorescence detector (SEM-EDXRF), with the objective to test the suitability of these techniques to identify the presence of small DU particles and measure their size distribution and the 235U/238U isotopic ratio (SIMS). Although the results do not permit any legitimate extrapolation to all the sites hit by the DU rounds used during the conflict, they indicated that there can be "spots ' where hundreds of thousands of particles may be present in a few milligrams of DU contaminated soil. The particle size distribution showed that most of the DU particles were <5 microm in diameter and more than 50% of the particles had a diameter <1.5 microm. Knowledge on DU particles is needed as a basis for the assessment of the potential environmental and health impacts of military use of DU, since it provides information on possible re-suspension and inhalation.

Distress in everyday life in people with poliomyelitis sequelae.

The prevalence of distress in aspects of perceived health and its relation to involvement of poliomyelitis sequelae were studied with the Nottingham Health Profile (NHP) in 113 outpatients (mean age 57 years). The leisure and employment situation was also recorded. Most distress was found in the NHP dimensions physical mobility, pain and energy, and least distress in social isolation. Most health-related problems were reported in housework, employment and leisure. Three-quarters of the persons were satisfied with their leisure, although many of them had problems. Fifty-nine per cent of the subjects of working age were in gainful employment, and no difference in employment rate due to the distribution of polio involvement was found. In comparison with norm values for the respective age groups, the subjects with poliomyelitis sequelae aged below 45 and 45-65 years had more distress in a larger number of NHP dimensions than older subjects.

Physical activity, muscle performance and quality of life in patients treated with chronic peritoneal dialysis.

OBJECTIVE: Today's medical treatment of patients with end-stage renal failure has increased their opportunities for an active lifestyle. The aim of this study was to describe the muscle performance, level of physical activity, independence in activities of daily living and quality of life in patients treated with chronic peritoneal dialysis. MATERIAL AND METHODS: The study investigated 33 patients (30-81 years old) treated with chronic peritoneal dialysis. The results were compared with an age-matched healthy reference group. Muscle mass was determined by measuring total body potassium, while maximal grip strength was measured with an electric force transducer. The ability to perform heel-lifts, walking speed and level of physical activity were also assessed, along with the extent to which patients were independent in activities of daily living (ADL) and satisfied with their health. RESULTS: Total body potassium was 97 +/- 11.6% of normal and correlated positively with the maximal grip strength (r = 0.658, p < 0.0002) and the maximal walking speed (r = 0.558, p < 0.0027). Maximal grip strength was 70% of the reference, the ability to perform heel-lifts was 49% of the reference, the walking speed was 85% the reference and the level of physical activity was 56% of expected. The patients were independent in ADL to a great extent and 52% of the patients were satisfied with their health. CONCLUSION: The peritoneal dialysis patients had a relatively good quality of life and were largely independent in ADL Further studies are needed to investigate whether it is possible to improve muscle performance and the level of physical activity with exercise and muscle training in these patients.

Ecological disturbances in intestinal microflora caused by clinafloxacin, an extended-spectrum quinolone.

BACKGROUND: The quinolones developed over the past few years have enhanced in vitro activity and a broader spectrum of antimicrobial activity compared to many other antimicrobial agents including the older quinolones. The present study focuses on the effect of clinafloxacin, a member of the new broad-spectrum quinolone class of antibiotics, on the normal intestinal microflora. SUBJECTS AND METHODS: A total of 12 healthy volunteers received clinafloxacin orally, 200 mg twice daily for 7 days. Fecal specimens were collected at defined intervals before, during and after the administration in order to study the effect of clinafloxacin on the intestinal microflora and to correlate this effect with fecal clinafloxacin concentrations. Intestinal microorganisms isolated before, during and 2 weeks after clinafloxacin administration were tested for their suseptibility to clinafloxacin. RESULTS: Oral administration of clinafloxacin resulted in high drug levels in feces (mean value 176.2 mg/kg on day 7) and pronounced ecological disturbances. The aerobic microflora was eradicated in 11 of the 12 subjects and the anaerobic microflora was strongly suppressed during administration. There was a significant emergence of clinafloxacin-resistant Bacteroides spp. strains (MIC > or = 4 mg/ml) during administration. The elevated MIC values still remained 2 weeks after discontinuation of the antibiotic (p < 0.001). CONCLUSION: The emergence of clinafloxacin-resistant Bacteroides spp. demonstrates the necessity of restricting prescription for particular indications in order to preserve the efficacy of the highly active broad-spectrum quinolones.